CS39A Zooplankton - Feeding, Reproduction, Growth and Molecular Diversity
Date: Tuesday, June 11, 2002
Time: 12:00:00 PM
Location: View Royal
 
MatthewsB, University of Victoria, Victoria, Canada, bmatthew@uvic.ca
Mazumder, A, , University of Victoria, Victoria, Canada, mazumder@uvic.ca
 
ZOOPLANKTON FEEDING BEHAVIORS IN LAKES AND RESERVOIRS INFERRED BY STABLE ISOTOPES
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Stable isotopes of 13C and 15N are increasingly being used in freshwater ecosystems to define food web patterns. Zooplankton are generally depleted in their d13C signature relative to their measured particulate organic matter (POM) food source. The degree of this depletion is greatest in oligotrophic lakes and may be species specific. Selective feeding by zooplankton on isotopically depleted phytoplankton will contribute to this depletion if the algal d13C signature is masked within a mixed POM size fraction. Zooplankton migration and feeding behaviors in a stratified water column also contributes to the d13C signature of zooplankton, provided that metalimnetic or hypolimnetic algae are depleted in d13C relative to epilimnetic algae. I discuss how the d13C of zooplankton provide information as to how and where different zooplankton species are feeding in the stratified water column of oligotrophic lakes and reservoirs. I propose an experimental design that addresses how selective feeding and vertical migration behavior contribute to the d13C signature of zooplankton.